"I know I was criticized for saying a couple of months ago in Florida that these 11 million folks in the shadows are already Americans, and I got pretty roundly criticized for that," Biden said at a Cinco de Mayo breakfast Monday, The Washington Post reported. "But they are Americans. They may not be citizens, but they are Americans.

"In the definition of Teddy Roosevelt, he said Americanism is not a question of birthplace or creed or line of descent, it's a question of principles, idealism, and character," the vice president explained. "And I would argue that those 11 million folks who have been here breaking their neck, working hard, they are Americans."

He made similar comments in December.

Biden also called on House Republicans, and specifically House Speaker John Boehner, to move forward with immigration reform.

"And it's time for John — he's a good man, John Boehner — to stand up and other Republicans to stand up," he said. "It's time for him to stand up, stand up, and not let the minority — I think it's a minority — of the Republican Party in the House keep us from moving in a way that will change the circumstances for millions and millions of lives."

The vice president said that if immigration reform is passed, it will be a "shot in the arm" for the United States.

"To continue the dreams of all the American people, we have got to get 11 million people out of the shadows," he said. "It's not just to benefit those 11 million people, it's badly needed for the country."

Biden also addressed immigration while speaking at the graduation ceremony at Miami Dade College on Saturday, in which he said that a "constant, substantial stream of immigrants" is key to the U.S. economy.